Influential short-seller warns of bubble in 3D printers

SAN FRANCISCO (Reuters) - Shares of companies that sell 3D printers fell on Thursday after Citron Research said they were vastly overvalued and that the technology, highlighted this week by U.S. President Barack Obama, has been hyped.

Makers of 3D printers in recent years have turned an evolving technology used by manufacturers for over two decades toward consumers, offering the prospect of producing everything from toys to tools in the home, and sending their share prices soaring.

Citron Research, run by California-based investor and notable short-seller Andrew Left, issued a report on Thursday accusing 3D Systems' Chief Executive Abe Reichental of exaggerating advances in 3D printing and contributing to a bubble in the shares of 3D printing companies.

"Appearances have become completely unhinged from reality when it comes to the mania created in so-called '3D Printing' stocks, and 3D Systems in particular," Citron Research said. "Behind every good bubble there is a good promoter, in this case we have the best in Abe Reichental."

Shares of 3D Systems Corporation, the biggest listed U.S. 3D printer maker, fell. So did shares of Stratasys and ExOne.

Citron Research focuses on stocks it believes have been fraudulently and intentionally overvalued. It said 3D Systems has made no significant advances in 3D printing technology in the past five years and that it has recently rehashed consumer products with little change.